When a driver turns a traveling direction of a vehicle to left or right during driving of the vehicle, the driver checks a left rear and a right rear through a left side mirror and a right side mirror. However, when the driver intends to check left and right blind spots which are not visible through the left and right side mirrors, the driver has to put his/her head out of a window and then to check the blind spots, and such a situation occurs more often when the vehicle is reversing. To improve the problems, recently, there has been proposed a camera installed at a rear side of the vehicle, and the camera allows the driver to easily park the vehicle by providing a rear image of the vehicle. Meanwhile, a wide-angle lens is applied to such a rear-view camera to ensure a wide view. However, since the wide-angle lens provides a distorted image having exaggerated perspective or the like due to characteristics thereof, it is difficult to exactly recognize an object located at a rear of the vehicle using only the image taken through the wide-angle lens.